fix to not start fwrites on sheet when it is initially created

src/Spout/Writer/Common/Manager/WorkbookManagerAbstract.php

@@ -131,8 +131,6 @@ abstract class WorkbookManagerAbstract implements WorkbookManagerInterface
         $worksheetFilePath = $this->getWorksheetFilePath($sheet);
         $worksheet = $this->entityFactory->createWorksheet($worksheetFilePath, $sheet);
 
-        $this->worksheetManager->startSheet($worksheet);
-
         $worksheets[] = $worksheet;
         $this->workbook->setWorksheets($worksheets);
 
@@ -157,6 +155,16 @@ abstract class WorkbookManagerAbstract implements WorkbookManagerInterface
         return $this->currentWorksheet;
     }
 
+    /**
+     * starts the current sheet and opens the file pointer
+     *
+     * @throws IOException
+     */
+    public function startCurrentSheet()
+    {
+        $this->worksheetManager->startSheet($this->getCurrentWorksheet());
+    }
+
     /**
      * Sets the given sheet as the current one. New data will be written to this sheet.
      * The writing will resume where it stopped (i.e. data won't be truncated).

src/Spout/Writer/Common/Manager/WorkbookManagerInterface.php

@@ -30,6 +30,11 @@ interface WorkbookManagerInterface
      */
     public function addNewSheetAndMakeItCurrent();
 
+    /**
+     * @return void starts the current sheet and opens its file pointer
+     */
+    public function startCurrentSheet();
+
     /**
      * @return Worksheet[] All the workbook's sheets
      */

src/Spout/Writer/WriterMultiSheetsAbstract.php

@@ -4,6 +4,7 @@ namespace Box\Spout\Writer;
 
 use Box\Spout\Common\Creator\HelperFactory;
 use Box\Spout\Common\Entity\Row;
+use Box\Spout\Common\Exception\SpoutException;
 use Box\Spout\Common\Helper\GlobalFunctionsHelper;
 use Box\Spout\Common\Manager\OptionsManagerInterface;
 use Box\Spout\Writer\Common\Creator\ManagerFactoryInterface;
@@ -107,6 +108,24 @@ abstract class WriterMultiSheetsAbstract extends WriterAbstract
         return $worksheet->getExternalSheet();
     }
 
+    public function startCurrentSheet()
+    {
+        $this->workbookManager->startCurrentSheet();
+    }
+
+    /**
+     * @param Row $row
+     * @throws WriterNotOpenedException|SpoutException
+     * @return WriterAbstract
+     */
+    public function addRow(Row $row)
+    {
+        if (!$this->workbookManager->getCurrentWorksheet()->getFilePointer()){
+            $this->startCurrentSheet();
+        }
+        return parent::addRow($row);
+    }
+
     /**
      * Returns the current sheet
      *